/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkProjectedTetrahedraMapper.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

/*
 * Copyright 2003 Sandia Corporation.
 * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
 * license for use of this work by or on behalf of the
 * U.S. Government. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that this Notice and any
 * statement of authorship are reproduced on all copies.
 */

#include "vtkProjectedTetrahedraMapper.h"

#include "vtkArrayDispatch.h"
#include "vtkCellArray.h"
#include "vtkCellCenterDepthSort.h"
#include "vtkCellData.h"
#include "vtkColorTransferFunction.h"
#include "vtkDoubleArray.h"
#include "vtkFloatArray.h"
#include "vtkGarbageCollector.h"
#include "vtkMath.h"
#include "vtkObjectFactory.h"
#include "vtkPiecewiseFunction.h"
#include "vtkPointData.h"
#include "vtkTimerLog.h"
#include "vtkUnsignedCharArray.h"
#include "vtkUnstructuredGrid.h"
#include "vtkVisibilitySort.h"
#include "vtkVolume.h"
#include "vtkVolumeProperty.h"

#include <algorithm>
#include <cmath>

//------------------------------------------------------------------------------
vtkCxxSetObjectMacro(vtkProjectedTetrahedraMapper, VisibilitySort, vtkVisibilitySort);

//------------------------------------------------------------------------------
// Return nullptr if no override is supplied.
vtkAbstractObjectFactoryNewMacro(vtkProjectedTetrahedraMapper);

//------------------------------------------------------------------------------

vtkProjectedTetrahedraMapper::vtkProjectedTetrahedraMapper()
{
  this->VisibilitySort = vtkCellCenterDepthSort::New();
}

vtkProjectedTetrahedraMapper::~vtkProjectedTetrahedraMapper()
{
  this->SetVisibilitySort(nullptr);
}

void vtkProjectedTetrahedraMapper::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "VisibilitySort: " << this->VisibilitySort << endl;
}

//------------------------------------------------------------------------------

void vtkProjectedTetrahedraMapper::ReportReferences(vtkGarbageCollector* collector)
{
  this->Superclass::ReportReferences(collector);

  vtkGarbageCollectorReport(collector, this->VisibilitySort, "VisibilitySort");
}

//------------------------------------------------------------------------------
namespace
{
struct TransformPointsWorker
{
  const float* Proj;
  const float* ModelView;
  float* OutPoints;

  TransformPointsWorker(const float* proj, const float* mv, float* out)
    : Proj(proj)
    , ModelView(mv)
    , OutPoints(out)
  {
  }

  template <class ArrayT>
  void operator()(ArrayT* in_points)
  {
    float mat[16];
    int row, col;
    vtkIdType i;
    vtkIdType num_points = in_points->GetNumberOfTuples();
    typename ArrayT::ValueType in_p[3];
    float* out_p;

    // Combine two transforms into one transform.
    for (col = 0; col < 4; col++)
    {
      for (row = 0; row < 4; row++)
      {
        mat[col * 4 + row] = (this->Proj[0 * 4 + row] * this->ModelView[col * 4 + 0] +
          this->Proj[1 * 4 + row] * this->ModelView[col * 4 + 1] +
          this->Proj[2 * 4 + row] * this->ModelView[col * 4 + 2] +
          this->Proj[3 * 4 + row] * this->ModelView[col * 4 + 3]);
      }
    }

    // Transform all points.
    for (i = 0, out_p = this->OutPoints; i < num_points; i++, out_p += 3)
    {
      in_points->GetTypedTuple(i, in_p);
      for (row = 0; row < 3; row++)
      {
        out_p[row] = (mat[0 * 4 + row] * in_p[0] + mat[1 * 4 + row] * in_p[1] +
          mat[2 * 4 + row] * in_p[2] + mat[3 * 4 + row]);
      }
    }

    // Check to see if we need to divide by w.
    if ((mat[0 * 4 + 3] != 0) || (mat[1 * 4 + 3] != 0) || (mat[2 * 4 + 3] != 0) ||
      (mat[3 * 4 + 3] != 1))
    {
      for (i = 0, out_p = this->OutPoints; i < num_points; i++, out_p += 3)
      {
        in_points->GetTypedTuple(i, in_p);
        float w = (mat[0 * 4 + 3] * in_p[0] + mat[1 * 4 + 3] * in_p[1] + mat[2 * 4 + 3] * in_p[2] +
          mat[3 * 4 + 3]);
        if (w > 0.0)
        {
          out_p[0] /= w;
          out_p[1] /= w;
          out_p[2] /= w;
        }
        else
        {
          // A negative w probably means the point is behind the viewer.  Things
          // can get screwy if we try to inverse-project that.  Instead, just
          // set the position somewhere very far behind us.
          out_p[2] = -VTK_FLOAT_MAX;
        }
      }
    }
  }
};
} // end anon namespace

//------------------------------------------------------------------------------
void vtkProjectedTetrahedraMapper::TransformPoints(vtkPoints* inPoints,
  const float projection_mat[16], const float modelview_mat[16], vtkFloatArray* outPoints)
{
  if (!inPoints)
  {
    return;
  }
  outPoints->SetNumberOfComponents(3);
  outPoints->SetNumberOfTuples(inPoints->GetNumberOfPoints());
  TransformPointsWorker worker(projection_mat, modelview_mat, outPoints->GetPointer(0));
  vtkArrayDispatch::Dispatch::Execute(inPoints->GetData(), worker);
}

//------------------------------------------------------------------------------

namespace vtkProjectedTetrahedraMapperNamespace
{
template <typename ColorArrayT, typename ScalarArrayT>
void MapScalarsToColorsImpl(
  ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars);
template <typename ColorArrayT, typename ScalarArrayT>
void MapIndependentComponents(
  ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars);
template <typename ColorArrayT, typename ScalarArrayT>
void Map2DependentComponents(
  ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars);
template <typename ColorArrayT, typename ScalarArrayT>
void Map4DependentComponents(ColorArrayT* colors, ScalarArrayT* scalars);

struct Worker
{
  vtkVolumeProperty* Property;

  Worker(vtkVolumeProperty* property)
    : Property(property)
  {
  }

  template <typename ColorArrayT, typename ScalarArrayT>
  void operator()(ColorArrayT* colors, ScalarArrayT* scalars)
  {
    MapScalarsToColorsImpl(colors, this->Property, scalars);
  }
};
}

void vtkProjectedTetrahedraMapper::MapScalarsToColors(
  vtkDataArray* colors, vtkVolumeProperty* property, vtkDataArray* scalars)
{
  using namespace vtkProjectedTetrahedraMapperNamespace;

  vtkDataArray* tmpColors;
  int castColors;

  if ((colors->GetDataType() == VTK_UNSIGNED_CHAR) &&
    (((scalars->GetDataType() != VTK_UNSIGNED_CHAR) || (property->GetIndependentComponents())) ||
      ((!property->GetIndependentComponents()) && (scalars->GetNumberOfComponents() == 2))))
  {
    // Special case.  Need to convert from range [0,1] to [0,255].
    tmpColors = vtkDoubleArray::New();
    castColors = 1;
  }
  else
  {
    tmpColors = colors;
    castColors = 0;
  }

  vtkIdType numscalars = scalars->GetNumberOfTuples();

  tmpColors->Initialize();
  tmpColors->SetNumberOfComponents(4);
  tmpColors->SetNumberOfTuples(numscalars);

  Worker worker(property);
  if (!vtkArrayDispatch::Dispatch2::Execute(tmpColors, scalars, worker))
  {
    vtkGenericWarningMacro("Dispatch failed for scalar array " << scalars->GetName());
  }

  if (castColors)
  {
    // Special case.  Need to convert from range [0,1] to [0,255].
    colors->Initialize();
    colors->SetNumberOfComponents(4);
    colors->SetNumberOfTuples(scalars->GetNumberOfTuples());

    unsigned char* c = static_cast<vtkUnsignedCharArray*>(colors)->GetPointer(0);

    for (vtkIdType i = 0; i < numscalars; i++, c += 4)
    {
      double* dc = tmpColors->GetTuple(i);
      c[0] = static_cast<unsigned char>(dc[0] * 255.9999);
      c[1] = static_cast<unsigned char>(dc[1] * 255.9999);
      c[2] = static_cast<unsigned char>(dc[2] * 255.9999);
      c[3] = static_cast<unsigned char>(dc[3] * 255.9999);
    }

    tmpColors->Delete();
  }
}

//------------------------------------------------------------------------------
namespace vtkProjectedTetrahedraMapperNamespace
{
template <typename ColorArrayT, typename ScalarArrayT>
void MapScalarsToColorsImpl(ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars)
{
  if (property->GetIndependentComponents())
  {
    MapIndependentComponents(colors, property, scalars);
  }
  else
  {
    switch (scalars->GetNumberOfComponents())
    {
      case 2:
        Map2DependentComponents(colors, property, scalars);
        break;
      case 4:
        Map4DependentComponents(colors, scalars);
        break;
      default:
        vtkGenericWarningMacro("Attempted to map scalar with " << scalars->GetNumberOfComponents()
                                                               << " with dependent components");
        break;
    }
  }
}

template <typename ColorArrayT, typename ScalarArrayT>
void MapIndependentComponents(
  ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars)
{
  // I don't really know what to do if there is more than one component.
  // How am I supposed to mix the resulting colors?  Since I don't know
  // what to do, and the whole thing seems kinda pointless anyway, I'm just
  // going to punt and copy over the first scalar.
  vtkIdType i;
  vtkIdType num_scalars = scalars->GetNumberOfTuples();

  typedef typename ScalarArrayT::ValueType ScalarType;
  typedef typename ColorArrayT::ValueType ColorType;
  ColorType c[4];

  if (property->GetColorChannels() == 1)
  {
    vtkPiecewiseFunction* gray = property->GetGrayTransferFunction();
    vtkPiecewiseFunction* alpha = property->GetScalarOpacity();

    for (i = 0; i < num_scalars; i++)
    {
      ScalarType s = scalars->GetTypedComponent(i, 0);
      c[0] = c[1] = c[2] = static_cast<ColorType>(gray->GetValue(s));
      c[3] = static_cast<ColorType>(alpha->GetValue(s));
      colors->SetTypedTuple(i, c);
    }
  }
  else
  {
    vtkColorTransferFunction* rgb = property->GetRGBTransferFunction();
    vtkPiecewiseFunction* alpha = property->GetScalarOpacity();

    int vectorMode = rgb->GetVectorMode();
    int vectorComponent = rgb->GetVectorComponent();

    for (i = 0; i < num_scalars; i++)
    {
      ScalarType s = 0.0;
      if (vectorMode == vtkScalarsToColors::COMPONENT)
      {
        s = scalars->GetTypedComponent(i, vectorComponent);
      }
      else
      {
        ScalarType sum = 0.0;
        for (int comp = 0; comp < scalars->GetNumberOfComponents(); ++comp)
        {
          ScalarType t = scalars->GetTypedComponent(i, comp);
          sum += t * t;
        }
        s = sqrt(sum);
      }

      double trgb[3];
      rgb->GetColor(s, trgb);
      c[0] = static_cast<ColorType>(trgb[0]);
      c[1] = static_cast<ColorType>(trgb[1]);
      c[2] = static_cast<ColorType>(trgb[2]);
      c[3] = static_cast<ColorType>(alpha->GetValue(s));
      colors->SetTypedTuple(i, c);
    }
  }
}

template <typename ColorArrayT, typename ScalarArrayT>
void Map2DependentComponents(
  ColorArrayT* colors, vtkVolumeProperty* property, ScalarArrayT* scalars)
{
  typedef typename ScalarArrayT::ValueType ScalarType;
  vtkColorTransferFunction* rgb = property->GetRGBTransferFunction();
  vtkPiecewiseFunction* alpha = property->GetScalarOpacity();
  vtkIdType num_scalars = scalars->GetNumberOfTuples();
  double rgbColor[4];
  ScalarType scalar[2];

  for (vtkIdType i = 0; i < num_scalars; i++)
  {
    scalars->GetTypedTuple(i, scalar);
    rgb->GetColor(scalar[0], rgbColor);
    rgbColor[3] = alpha->GetValue(scalar[1]);
    colors->SetTuple(i, rgbColor);
  }
}

template <typename ColorArrayT, typename ScalarArrayT>
void Map4DependentComponents(ColorArrayT* colors, ScalarArrayT* scalars)
{
  double val[4];
  vtkIdType num_scalars = scalars->GetNumberOfTuples();
  for (vtkIdType i = 0; i < num_scalars; i++)
  {
    scalars->GetTuple(i, val);
    colors->SetTuple(i, val);
  }
}

}
